Topic
Circular polarization
About: Circular polarization is a research topic. Over the lifetime, 15201 publications have been published within this topic receiving 234418 citations.
Papers published on a yearly basis
Papers
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TL;DR: This work presents a method allowing for the imposition of two independent and arbitrary phase profiles on any pair of orthogonal states of polarization-linear, circular, or elliptical-relying only on simple, linearly birefringent wave plate elements arranged into metasurfaces.
Abstract: We present a method allowing for the imposition of two independent and arbitrary phase profiles on any pair of orthogonal states of polarization-linear, circular, or elliptical-relying only on simple, linearly birefringent wave plate elements arranged into metasurfaces. This stands in contrast to previous designs which could only address orthogonal linear, and to a limited extent, circular polarizations. Using this approach, we demonstrate chiral holograms characterized by fully independent far fields for each circular polarization and elliptical polarization beam splitters, both in the visible. This approach significantly expands the scope of metasurface polarization optics.
805 citations
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TL;DR: The device demonstrates a route to exploit the valley degree of freedom and the possibility to develop a valley-optoelectronics technology and reports an electrically switchable, circularly polarized light source based on the material’s valleydegree of freedom.
Abstract: Tungsten diselenide (WSe2) and related transition metal dichalcogenides exhibit interesting optoelectronic properties owing to their peculiar band structures originating from the valley degree of freedom. Although the optical generation and detection of valley polarization has been demonstrated, it has been difficult to realize active valley-dependent functions suitable for device applications. We report an electrically switchable, circularly polarized light source based on the material's valley degree of freedom. Our WSe2-based ambipolar transistors emit circularly polarized electroluminescence from p-i-n junctions electrostatically formed in transistor channels. This phenomenon can be explained qualitatively by the electron-hole overlap controlled by the in-plane electric field. Our device demonstrates a route to exploit the valley degree of freedom and the possibility to develop a valley-optoelectronics technology.
688 citations
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TL;DR: In this paper, an artificial impedance surface that is implemented as an array of sub-wavelength metallic patches on a grounded dielectric substrate is designed to scatter a known input wave into a desired output wave.
Abstract: We have developed a method for controlling electromagnetic surface wave propagation and radiation from complex metallic shapes. The object is covered with an artificial impedance surface that is implemented as an array of sub-wavelength metallic patches on a grounded dielectric substrate. We pattern the effective impedance over the surface by varying the size of the metallic patches. Using a holographic technique, we design the surface to scatter a known input wave into a desired output wave. Furthermore, by varying the shape of the patches we can create anisotropic surfaces with tensor impedance properties that provide control over polarization. As an example, we demonstrate a tensor impedance surface that produces circularly polarized radiation from a linearly polarized source.
682 citations
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TL;DR: In this paper, a gradient in the pitch of the cholesteric helix was introduced to obtain reflection of one of the two circularly polarized components over the entire visible spectrum, which would greatly improve the light yield and energy efficiency of liquidcrystal display devices.
Abstract: CHOLESTERIC liquid crystals, in which the orientation of the molecules varies in a helical fashion, are used for optical filtering of circularly polarized light, for example in liquidcrystal displays. They reflect circularly polarized incident light of the same handed ness as the cholesteric helix, and in a wavelength band that depends on the helical pitch (repeat distance). This pitch can be selected by careful design of the liquidcrystal molecules or by mixing cholesteric materials with nematic (linearly oriented) liquid crystals, which tend to increase the pitch. Stable optical filters are produced by crosslinking the cholesteric molecules by photopolymerization1; these filters typically have a reflection wavelength bandwidth of ∼50 nm. Here we show that, by introducing a gradient in the pitch of the cholesteric helix, we can obtain reflection of one of the two circularly polarized components over the entire visible spectrum. Polarizers with such broadband reflectivity would greatly improve the light yield and energy efficiency of liquidcrystal display devices.
644 citations
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TL;DR: An organic field effect transistor featuring the chiral molecule helicene acts as a photodetector that is able to distinguish between left and right-handed circularly polarized light.
Abstract: An organic field effect transistor featuring the chiral molecule helicene acts as a photodetector that is able to distinguish between left- and right-handed circularly polarized light.
642 citations